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Wiring a float switch depends on your setup, but here are general guidelines:
Piggyback Float (for single pump): This is the simplest. A piggyback float switch has a plug end that you plug into your outlet, and then you plug the pump into the back of the float’s plug
The float acts as an automatic switch: when the float rises, it completes the circuit and supplies power to the pump. For this, just make sure the float’s cord is securely routed and that it’s a pump-down (NO) float for an emptying pump (most piggyback floats sold for sump/sewage use are pump-down).
Hardwired to a Pump or Panel: If the float has cable leads, you’ll typically wire it in series with the pump’s control circuit. For a direct pump control, the float’s two wires go in line with the pump’s hot lead (for 120/230V single-phase) – effectively the float is the switch that either completes or breaks the live supply to the pump. Always disconnect power when doing this wiring. Ensure you use the correct float (NO vs NC) so that it closes the circuit when you want the pump running
For example, a normally open float’s leads would be wired such that when the float rises (NO closes), it completes the circuit to the pump.
Multiple Float/Panel Wiring: In an industrial control panel, floats usually connect to low-voltage inputs. Each float will have two (or three) conductors that land on terminal blocks in the panel. One common schema: a “stop” float (lowest) and a “start” float (next higher) together control a pump via a latching relay in the panel. A high-level float might wire to an alarm input. Follow the control panel’s schematic – it will indicate which terminals the float wires go to. Label each float’s cable so you don’t mix them up.
Electrical Safety: Use waterproof connectors or cord grips when bringing float wires into a junction box or control panel (to keep the connection dry and secure). Do not run float switch cables in the same conduit as high-power wires unless rated for it – electrical noise can sometimes affect sensor wires. For long cable runs, check if there’s any issue with voltage drop or interference (generally not a problem for simple float switches). If the lift station is a hazardous location, the floats must be wired through an intrinsically safe barrier in the control panel
(consult a qualified electrician for such cases).